Mold for composite articles



F. R. HORNIG MOLD FOR COMPOSITE ARTICLES July 31, 1928.

Filed March '2, 1927' INVENTOR I W Y ATTORNEY Patented July 31, 1928.

UNITED. STATES v l,678,812 PATENT oF Ice.

FRED R. HORNIG, OF MILWAUKEE, WISCONSIN.

MOLD FOR COMPOSITE ARTICLES.

Application filed March 7, 1927. Serial No. 173,311.

My invention relates to improvements in plaster molds.

In forming and constructing molds for plaster bodies in which electric appliances,

such as electric lamp sockets, are to be embedded, I have found that expensive cleaning processes may be avoided if my invenmold so as to exclude the liquid or molten material from its inner portions while the molding or pouring process is being accomplished, and to provide a positioning jack which will firmly holdan electric fixture in a mold during the molding process, but which will release the fixture easily when the mold is withdrawn from the finished article.

In the drawings:

Figure 1 is a plan view of a mold showing the arrangement of the various acks therein with light sockets in place upon them.

Figure 2 is a vertical section through a portion of a mold and through the axis of one of my improved jacks.

Figure 3 is a side view of one of my jacks.

Figure 4 is a plan view of the jack shown in Figure 3.

Like parts are identified by the same reference characters throughout the several views.

Figure 1 shows a mold 1 in the shape of a star 2 wherein are positioned sixteen of my improved jacks 3 supporting light sockets 4. The mold 1 is placed upon a table or plane surface board 5 which forms the removable bottom of the mold to which the various jacks are secured by means of screws 6 which extend through the board 5 and into threaded engagement with the jacks 3. A taper bored hole 7 extending transversely and at a slight incline through the body of each of the jacks 8 forms a retaining cavity for two small balls 8 which are separated from each other and forced apart by a compression spring 9. The larger end of the tapered bore is swaged after the two balls and spring are inserted in the bore to prevent the spring from forcing the ball out of the larger end of the bore; The smaller end of the bore is only large enough to permit a small part of one of the balls to protrude beyond the side of the jack. A curved shoulder at 10 is provided to conform to the curved margins of the light socket 4c.

lVhen a star is to be poured into my mold, each of the jacks as described above is used as a positioning device for a light socket which may be forced down upon the jack and then rotated so as to thread the socket down upon the shoulders 10, the balls coacting with the threaded wall of the socket to resiliently retain the margins of the socket against the shoulder during the pouring process. When the liquid material poured around the socket has hardened, the mold 1 may be withdrawn from the board 5, and at the same time, the sockets embedded in the solidified material will be permitted to withdraw from the jack when the balls 8 are crowded within the bore 7 against the compression of the spring 9. When the molded article is given its final finish, it will be found that the outer margins, of the socket have, in conjunction with the shoulder 10 of the jack, excluded all plaster or other molten material from the interior of the socket, and that the bond between the socket and the solidified surrounding material has not been disturbed by the forcible withdrawal of the jack from the socket. This is important when wiring such as that shown at 11 in Figure 1 is to be embedded in the solidified material for the soldered joints, such as 12 in Figure 1, must not be disturbed.

I claim:

1. In a mold for plastic material, the combination with a hollow fixture provided with corrugated walls and adapted to be permanently embedded in the plastic material, of a jack for releasably positioning said fixture and provided with a resilient protuberance for registry with the corrugations in the wall of the fixture.

2. In a mold for plastic material, the combination with a hollow fixture having a threaded wall, of a jack for releasably positioning said fixture in said mold, and protuberances resiliently extending from the jack and arranged to cooperate with said thread, said jack having a base against which said fixture may be forced by the interaction of said thread and protuberances,

3. In a mold for plastic material, the combination with a fixture having corrugated.

Ill

walls with extendedfree marginssurrounding a hollow portion, of a ack provided with a resilient protuberance adapted to coact with the corrugations of said wall 'for releasably positioning the fixture in the mold whereby to cause the margins of the fixture to co-act with the jack to exclude plastic material from the hollow portion.

4. As an article of manufacture a positioning pinor jackcomprising a cylindrical {fjor retaining the balls partially within the ore.

5. In a mold, the combination with a jack comprising a cylindrical body and an annular base, of a resilient protuberance upon the cylindrical body, and a fixture provided with corrugatedwalls surrounding a hollow portion and adapted to be releasably mounted over! thBwjlGk whereby the walls of; the

fixture may be caused to resiliently-and re-- leasably coactwiththe annular base of the 25 j ack.

FRED R. HORNIG. 

